Field effect transistor (FET) sensing cells are often used for sensing and detecting at least one of ions, bio-entities or biomolecules. FET sensing cells operate on the basis of at least one of electronic, electrochemical, optical, or mechanical detection principles. FET sensing cells that include transistors are sensors that electrically sense charges, photons, and mechanical properties of ions, bio-entities or biomolecules. The detection is performed by detecting the bio-entities, ions or biomolecules themselves, or through interaction and reaction between specified receptors and bio-entities/biomolecules. Such FET sensing cells are manufactured using semiconductor processes and are applicable to integrated circuits (ICs) and microelectromechanical systems (MEMS).
Ion sensitive field effect transistors (ISFETs) and biologically sensitive field-effect transistors, or bio-organic field-effect transistors (BioFETs) are two types of FET sensing cells that include a transistor for electrically sensing ions, biomolecules or bio-entities.